Soil Health Fact Sheet 1 Soil Health Fact Sheets – Ocean County Basins USDA, Natural Resources Conservation Service - New Jersey January 2011

What are Stormwater Basins? Stormwater basins are impoundments or excavated basins for the short term detention of stormwater runoff from a completed development area followed by controlled release from the structure at downstream, pre‐development flow rates. There are several types of detention devices, the most common being the dry and the extended dry detention basin. These structures hold and release the water through a controlled outlet over specified time period based on the design criteria. The extended detention basin drains more slowly or may retain a permanent pool of water.

Stormwater basins are facilities constructed Avenue Basin now drains within 48 hours of a rain event due within highly permeable soils that provide temporary to the benefits of Soil Health restoration. Water is able to infiltrate storage of stormwater runoff. An does through the soil because soil is no longer compacted and not normally have a structural outlet to runoff vegetation has become established. Ocean County Soil Conservation District has identified 3500 basins within the county. from a specific design storm. Instead, outflow from an infiltration basin is through the surrounding soil. An What is Soil? infiltration basin may also be combined with an Soil is a natural body comprised of solids (minerals and extended detention basin to provide additional runoff organic matter), liquid, and gases that occurs on the storage from both stormwater quality and quantity land surface. It consists of mineral particles of different management. sizes (sand, silt, and ), organic matter, water, air,

and numerous living organisms. Soil has biological, chemical, and physical properties. It is not an inert, lifeless medium but rather a living matrix of solid, liquid, and gas, with microorganisms, earthworms, fungi, bacteria, insects, living and decayed organic matter, water, air, and nutrients, all engaged in a biological and chemical give‐and‐take of energy and elements.

What is Soil Quality? Soil Quality is simply how well soil does what we want it to do. More specifically, soil quality is the capacity of a specific kind of soil to function, within natural or managed ecosystems, to sustain plant and animal productivity, maintain or enhance water and air quality, Bay Avenue Basin held water for 35 years prior to soil restoration. and support human health and habitation. In Soil was unable to function with standing water 365 days a year. stormwater detention basins soil quality may mean a

fully functioning basin, providing the results it was designed for. Soil Quality is the integration of the physical, chemical and biological properties of the soil.

soil has more room for roots than soils with bedrock near the surface. These characteristics do not change easily. Dynamic soil quality describes the changes that result from management decisions. For example, soil compaction occurs from the use of heavy equipment under the wrong moisture conditions.

Soil regulates and partitions rainfall. Soil also regulates flow and storage of water and solutes, including nitrogen, phosphorus, pesticides and other nutrients and compounds that are in dissolved water. Soil stores, moderates the release of, and cycles plant nutrients and other elements. Soil acts as a living filter that serves to Note the compacted zone below the roots at the bottom of the photo. This compacted soil prevents roots from growing and can prevent water from protect and enhance our entire ecosystem. Soil also infiltrating through the soil profile. supports structures and preserves and protects archaeological treasures. Changes in the capacity of a soil to function are reflected in soil properties that change in response to management or climate.

How does Soil Health in Stormwater Basins affect Quantity and Quality? Infiltrated water is critical in that it recharges groundwater supplies and provides base flow to , while maintaining and habitat needed for aquatic organisms. Stormwater runoff is associated with flooding, delivery of pollutants, , decreased base flow, poor water quality, and reduced richness and abundance of fish species. Infiltration basins are used to remove Soil in this basin has been compacted due to improper construction pollutants and to infiltrate stormwater back into the methods that led to this basin retaining water and causing subsequent ground rather than have them leave the site in the form compaction from the sheer weight of the water column. of erosion. Under natural conditions, approximately 10% of precipitation runs over the surface of the land Compaction and about 50% infiltrates back into the soil. This 50% is Soil Compaction is a common reason for basins to not vital to environmental health as it is the water that function properly. Low organic matter levels in the soils replenishes groundwater supplies and provides base of basins can be a potential reason for basin failure. flow to streams. The remaining 40% of stormwater is Organic residues on the soil surface and within the soil used in plant uptake and evapo‐transpiration. profile have been shown to cushion the effects of compaction. Organic matter acts like a sponge in that What are Inherent and Dynamic soil properties? the organic matter is compressed and then springs back Soil has both inherent and dynamic qualities. Inherent to its normal shape. Plant debris and residues attach to soil quality is a soil’s natural ability to function. For soil particles and keeps them from compacting. Organic example, sandy soil drains faster than clayey soil. Deep matter binds micro‐aggregates into macro‐aggregates in Soil Health Fact Sheet 1 Stormwater Basins the soil. Soil compaction has a biological component change in soil color, ephemeral , , runoff, and the root cause of soil compaction is a lack of plant response, weed species, blowing soil and actively growing plants and active roots in the soil. are only a few examples of potential Plant roots create voids and macro‐pores in the soil for indicators. Physical indicators are related to the air and water movement. arrangement of solid particles and pores. Examples include topsoil depth, bulk density, porosity, aggregate Plant roots act like a biological valve to control the stability, texture, crusting, and compaction. Physical amount of oxygen in the soil to preserve soil organic indicators primarily reflect limitations to root growth, matter. Plant roots supply food for soil microbes and seedling emergence, infiltration, or movement of water soil fauna. Residual organic residues (plants, roots, within the soil profile. Chemical indicators include microbes) are lighter and less dense than soil particles. measurements of pH, , organic matter, Polysaccharides from plants and glomalin (soil glue) phosphorus concentrations, cation‐exchange capacity, from fungus weakly hold the micro‐aggregates together nutrient cycling, and concentrations of elements that but are consumed by bacteria so they need to be may be potential contaminants or those that are continually reproduced in the soil to improve soil needed for plant growth and development. The soil’s structure. chemical condition affects soil‐plant relations, water quality, buffering capacities, availability of nutrients and Organic Matter is the Key! waters to plants other soil organisms, mobility of Many soil properties impact soil health but organic contaminants, and some physical conditions such as the matter is the most limiting factor. It affects several tendency for a surface soil crust to form. Biological critical soil functions and can be manipulated by indicators include measurements of micro‐ and macro‐ management practices. Organic matter enhances water organisms, their activity, or byproducts. Respiration and nutrient holding capacity and improves overall soil rates can be used to detect soil microbial activity, structure. Managing for soil carbon or organic matter specifically soil microbial decomposition of organic enhances the productivity and environmental quality of matter, which is the key to the formation and stability our ecosystems. Soils high in organic matter content of soil aggregates. can typically reduce the severity and costs of natural disasters such as drought, and diseases. When the soil is disturbed it loses its’ natural ability to Moreover, increasing soil organic matter levels can absorb and infiltrate rainfall making it necessary to reduce atmospheric CO2 levels that contribute to collect, channel, store and filter stormwater. climate change. Management choices affect the amount of soil organic matter, soil structure, soil depth, water and nutrient holding capacity. Soils respond differently to management depending on the inherent properties of the soil and the surrounding landscape.

What are Soil Health Indicators that can help determine overall Soil Function? Indicators of soil quality can be categorized into four general groups: visual, physical, chemical and biological. Visual indicators may be obtained from observation or Notice the good root development and abundant pore space. This pore space allows for nutrients and water to flow and be utilized by the plants photographic interpretation. Exposure of subsoil, above ground. landscaping means using plants, trees, and shrubs How does Soil Structure and Bulk Density help known to exist in the project area during pre‐settlement determine Soil Health? times. Native plants and their functions have a number Soil structure is of particular importance in the of advantages over their non‐native counterparts when absorption of water and the circulation of air. A used as landscaping for a stormwater basin. The goals desirable structure should have a high proportion of of the landscaping plan range from an improvement in medium‐sized aggregates and an appreciable number of water quality to provision of wildlife food and habitat. If large pores through which water and air can move. wisely chosen, native plants are also esthetically Good soil structure is crucial to proper drainage, pleasing and blend well with most surrounding infiltration, and productivity. In soils with poor developments and landscapes. structure, root penetration is limited thus reducing the plants access to water and nutrients. There are three Use of native plants in the several landscaping zones very important aspects of soil structure. They are (a) the around a basin can provide a rich visual environment as arrangement into aggregates of a desirable shape and well as wildlife habitat. The combination of wetland size, (b) the stability of the aggregate, and (c) the plants with flowering prairie plants and, in some cases, configuration of the pores, that is, whether or not they trees and shrubs in upland areas provides far more are connected to the surface by channels or isolated. visual appeal throughout the year than large areas of Pores that are not connected to the surface do not mowed lawn. Once established, native vegetation may improve infiltration. Aggregates that are stable in water require far less maintenance. This benefit is particularly permit a greater rate of absorption of water and greater important as suburban growth replaces historic resistance to erosion. Aggregates that are unstable in woodlots and fields. In the upland areas of a water tend to slake and disperse. These aggregates, stormwater basin, for example, tall grasses, trees and when exposed to raindrops, are particularly subject to shrubs provide habitat for a variety of song birds, dispersion and the resultant crusting of soils. The amphibians and reptiles and can provide critical habitat stability of aggregates is due to the kind of clay, the for native pollinators. chemical elements associated with the clay, the nature of the products of decomposition or organic matter, What are the principles of stormwater basin and the nature of the microbial population. success?  Add organic matter in the form of vegetation or Bulk density Bulk density refers to the weight of the mulch. oven‐dry soil with its natural structural arrangement.  Keep ground covered with vegetation or mulch The pore space between the soil particles is a part of as soon as possible after disturbance. the volume of soil measured for bulk density. Bulk  Prevent or remediate compaction. density is expressed as grams per cubic centimeter.  Schedule excavation during low rainfall periods, The variation in bulk density is due largely to the when possible. difference in total pore space. Because finer textured  Fit development to the terrain. soils have higher percentages of total pore space, it  Keep soil covered with vegetation and don’t follows that finer textured soils have smaller bulk allow it to be exposed for months or years. density values. Compacted soils have lower percentages  Divert water from disturbed areas until they are of total pore space and therefore, higher bulk densities. stabilized. High and low bulk densities have great influences on  Control concentrated flow and runoff to reduce engineering properties, water movement, rooting depth the volume and velocity of water from work of plants, and many other physical limitations for soil sites to prevent the formation of gullies. interpretations. Bulk density is a critical soil property in  Minimize the length and steepness of slopes. assessing proper soil function.  Prevent from leaving the site.

 Inspect and maintain structural control How can native vegetation restore soil function in measures. stormwater basins?  Plan and install windbreaks if necessary. Stormwater basins have become so common that they  Avoid compaction by restricting the use of represent an integral part of our growing urban and trucks and heavy equipment to limited areas. suburban landscape. Landscaping these stormwater basins with native plants can increase their value and improve their water treatment functions. Native Soil Health Fact Sheet 1 Stormwater Basins

Where can I get more information on Soil Health? References ANJEC. Municipal Options for Stormwater Management. ANJEC For additional information go to the following websites: Resource Paper .  www.nj.nrcs.usda.gov  www.soils.usda.gov/sqi Hanks, D. and A. Lewandowski. Protecting Urban Soil Quality:  www.soilhealth.org Examples for Landscape Codes and Specifications. USDA NRCS.

DEQ NW Region Oregon. Restoring Soil Health to Urbanized Lands. The full series of Soil Quality Information Sheets is available at http://soils.usda.gov/sqi DeVries, A. Health From the Soil.

NJDEP. NJ Stormwater Best Management Practices Manual.

NRCS Soil Quality Institute. Soil Quality Tech Note No. 5 Managing Soil Organic Matter The Key to Air & Water Quality.

NRCS Soil Quality Institute. Soil Quality Urban Tech Note 1 Erosion & Sedimentation on Construction Sites.

NRCS Soil Quality Institute. Soil Quality Urban Tech Note No. 2 Urban Soil Compaction.

Pennsylvania Environmental Council. Improving Stromwater Detention Basins for Better Stormwater Managment.

Raabe, C. Basin Basics Dig and Drop‐ Not Rock & Roll

University of Wisconsin‐Extension & Wisconsin Department of Natural Resources. Storm Water Basins Using natural landscaping for water quality & esthetics.

USGS Water Science for Schools. The Water Cycle: Infiltration.

William C. Lucas Integrated Land Mangement Inc. Modeling Impervious Area Disconnection with SWMM.

This publication has been a joint effort between the USDA Natural Resources Conservation Service NJ and the Ocean County Soil Conservation District.

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